Mainemon's rampage, and the restart it caused. Leaving behind the distressed Meiko, Taichi and the others headed to the Digital World. The reunited Digimon partners had lost all their memories up to that point. The chosen children reached out to reestablish their bond, and the Digimon responded. However, only Biyomon was still wary even after evolving to the adult stage... "So I don't know about the past!" Biyomon was distrustful of Sora's kindness, who cared more about others than himself. Taichi and Yamato couldn't find the words to say to Sora, who stood there for a long time because of her injury. What should they do next in the Digital World? In front of everyone who was discussing this, Mainemon suddenly appeared and then disappeared. He somehow retained his original memories, and wandered around in tears while looking for Meiko. Seeing this scene, the children made up their minds to travel to the Digital World to save Mainemon. However, the figure of the man who drove the Four Dark Lords appeared in front of them. At this time, Nishijima in the real world receives a report of Himekawa's disappearance. He investigates the matter and finds out that there is a hidden purpose behind Himekawa's actions so far. This matter is also related to something in the past that determined the fate of the two...